The effect of rotation speed and advancement with three forms of tool pin geometry on the tensile strength of the joint area of ۲۰۲۴-T۳ to ۷۰۷۵-T۶ aluminum alloys butt by FSW process

In this study, the microscopic structure and mechanical properties of the joint surface of two ۲۰۲۴-T۳ and ۷۰۷۵-T۶ machine alloys were investigated. Combined center design (RSM) design was used to optimize the test and the effect of effective factors on the weld joint. Welding is performed using FSW process with a tool made of hot-rolled steel in three pins with tool geometry with cylindrical, conical and square cross-sections with a rotational speed of ۸۰۰-۱۲۰۰ rpm and a forward speed of ۱۰-۵۰ mm per minute. A scanning light and electron microscope was used to examine the junction area. The results show a microstructure with the size of elongated and grown grains in the HAZ region and the size of very fine and banded grains in the junction of two sheets that have intermetallic compounds and different sediments at the cross-sectional area. After analyzing the overall performance by tensile test and designing the experiment withmini-tab software, it can be found that among the variable factors, respectively, at the cross-section geometry of the tool pin, rotational speed and at the last tool advance speed are the most influential factors on tensile strength and area. The surface of the weld is elastic. The highest tensile strength was obtained in the area of connection to the tool pin with a cylindrical cross-section with a rotational speed of ۱۱۳۲ rpm and a forward speed of ۳۲ mm / min. The failure zone in the tensile test occurred in the HAZ zone in the ۲۰۲۴ company alloy.

کلیدواژه ها:

FSW ، tool geometry pin ، connection of ۲۰۲۴-T۳ and ۷۰۷۵-T۶ aluminum.